/Engine/Source/Editor/EditorWidgets/Public/Filters/CustomClassFilterData.h
You can provide anIAssetTypeActionsfor your type to get all the information from that
FCustomClassFilterData ( [UAssetDefinition](API\Editor\AssetDefinition\UAssetDefinition) * InAssetDefinition, const [FAssetFilterData](API\Editor\AssetDefinition\Misc\FAssetFilterData) & InAssetTypeAction )